Training materials
Authors: Hadley Wickham
and Contributors: Alex Ostrovsky or Allegra Via or Armin Fuchs or Celia van Gelder or Hadley Wickham or Yvonne Kallberg
Authors: Hadley Wickham
and Contributors: Alex Ostrovsky or Allegra Via or Armin Fuchs or Celia van Gelder or Hadley Wickham or Yvonne Kallberg